This invention relates to hydraulic systems.
More particularly, the present invention relates to controlling hydraulic systems.
In a further and more specific aspect, the instant invention concerns control of a hydraulically operated loader mechanism.
Hydraulic cylinders have been used to provide the motive force for mechanical articulated assemblies for many years. They are particularly useful when great force is required. When employing hydraulic cylinders there has conventionally been two ways to control hydraulic movement such as extension and retraction of the cylinder. The least complex mechanically is to simply let an operator control the cylinder and extend and retract it as necessary. While effective in very simple applications, this approach can be less than satisfactory in more complex systems having multiple articulations. Additionally, close supervision of the articulated device is not always possible. The other approach is to employ limit switches to indicate position of the articulated segments or a combination of the two approaches. Limit switches have limitations which often necessitate the combined approach. Specifically, this is the case when it is necessary to vary a motion such as to adapt to a situation. Additionally, limit switches are relatively expensive and can be a main trouble spot with frequent maintenance required.
A specific example of a complex articulated system is a loading arm for refuse collection. The systems employ hydraulic cylinders to extend and retract, pivot, dump and grip. Some of these functions do not vary, and limit switches are effective. Others, such as extending to grip a container can vary and require an observer. Loading arms typically employ an operator who must be located near the container for proper manipulation and limit switches which require high maintenance.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide a new and improved system for measuring hydraulic movements.
Another object of the invention is to provide a new and improved system for controlling hydraulic systems.
And another object of the invention is to provide a new and improved loading mechanism for loading refuse in a refuse vehicle.
Briefly, to achieve the desired objects of the instant invention in accordance with a preferred embodiment thereof, provided is a system for measuring the distance of a hydraulic movement. The system includes an engine supplying power, a hydraulic cylinder for supplying hydraulic movement, and a pump coupled to the hydraulic cylinder for providing hydraulic fluid to the hydraulic cylinder. A power take off is coupled to the engine and supplies power from the engine to the pump. A measuring device measures the amount of fluid provided to the hydraulic cylinder by counting engine revolutions.
Also provided is a method of operating a mechanized refuse collection vehicle including providing a refuse collection vehicle having an engine supplying power, an extendable arm moveable between an extended position and a retracted position by a hydraulic cylinder, the hydraulic cylinder providing an extension movement of the extendable arm toward the extended position and a retraction movement of the extendable arm toward the retracted position, a gripping mechanism coupled to the extendable arm and movable between an open configuration and a gripping configuration, and a pump coupled to the hydraulic cylinder for providing hydraulic fluid to the hydraulic cylinder and driven by the engine. A control system is provided including a computational device and a first control and a second control. The computational device measures the amount of fluid provide to the hydraulic cylinder by counting revolutions of the engine. The first control is actuated to accomplish a discharge cycle including extending the extendable arm in an extension movement, ending the extension movement of the extendable arm and ending counting by the computational device. The computational device factors the total count to determine the distance of the movement. The cycle continues by gripping a container, retracting the extendable arm to the retracted position and moving the gripping mechanism into a dumping orientation over the vehicle. The second control is actuated to accomplish a return cycle including lowering the extendable arm, recreating the extension movement by actuating the hydraulic cylinder and counting the engine revolutions, comparing the count to the stored count, and ending the movement when the counts match.